feat(M6): Weitere Hosts — MiniApps in Fenstern + AI-Agenten-Ausgabe-Bloecke (#364)

- Windows-Host: openMiniAppWindow-Helper + MiniAppWindowContent (windowStore);
  Oeffnen-Buttons im Chat-Block (MiniAppBlock) und Dashboard-Widget
- AI-Agenten-Host: Core-Tool send_miniapp (app/ai/miniapp_tools.py) —
  miniapp-Block in Agent-Chat (approval_request-Praezedenz), Permission
  fail-closed gegen aufrufenden User pro App; Registrierung im lifespan
- agent_loop: tool_context + agent_name (Raum-Aufloesung)
- Fix: MiniAppBlock nutzt useMiniapps (component-Feld) statt Legacy /comm/miniapps
- Tests: M6 7/7 (TDD rot->gruen), Backend-Regression 57/57, Vitest 26/26
  (4 neue Window-Tests), tsc clean, build OK

app/ai/agent_loop.py

@@ -197,6 +197,7 @@ async def run_react_loop(
         "tenant_id": str(tenant_id),
         "user_id": str(user_id),
         "db": db,
+        "agent_name": getattr(agent_definition, "name", "Agent"),
     }
 
     # Audit helper — records every tool call in the audit log.